Hitachi turntable - UK Vintage Radio Repair and Restoration Discussion Forum

ITAM805 · 27th Mar 2017, 4:37 pm

Split from this thread - I have this turntable from 1980 that I want to service.

Not sure of the ID other than it's named 'Unitorque'. It runs intermittently so I'm guessing there's a power supply problem or perhaps a hidden micro switch?

Can anyone help with how I get the platter off, and what to lube it with? There's a brass threaded cap underneath the spindle but it's on there pretty tight, molegrips wouldn't budge it !

Many thanks

Edward Huggins · 27th Mar 2017, 4:58 pm

This looks like it's a seperate unit from the rest of the kit, is that right? Is that the brass turntable boss you're trying to remove. Why? The platter will come off without putting a crude wrench on this. Use sewing machine oil to Lube. There should be a circlip on the centre spindle to release the platter.

dseymo1 · 27th Mar 2017, 5:14 pm

It looks like a typical Japanese belt-drive turntable. I'd expect the platter to lift off fairly easily, perhaps with a light tap from a mallet to the spindle while suspending the unit by the platter (takes two pairs of hands ideally).
is the belt loose and slipping, perhaps?
I'd use SAE 30 motor oil, but a few drops of pretty much any medium-bodied oil will do.

Edit: Edward was replying at the same time. There may indeed be a circlip, but I can't see one in this case.

paulsherwin · 27th Mar 2017, 5:16 pm

I agree it looks like belt drive, but it clearly has 'Direct Drive' printed on it.

There will be microswitches activated by the arm. All these DD autos are much of a muchness.

I would also use something heavier than sewing machine oil, though it doesn't really matter so long as the main bearing is well lubricated.

ITAM805 · 27th Mar 2017, 5:42 pm

Thanks guys. It's direct drive no belts. It doesn't just lift off and I can't see any circlips either? Edward, yes it's part of the music centre in the link.

Thanks for the lube advice.

Station X · 27th Mar 2017, 5:46 pm

Looks like it could be a brass shaft in a brass bearing. Does the turntable lift slightly so that the shaft slides in the bearing?

There's a hole in the side of the shaft. Does it conceal a grub screw, or possibly accomodate a 'C' spanner?

Left Hand Thread?

ITAM805 · 27th Mar 2017, 7:04 pm

Thanks Graham, there's no up/down movement on the platter. Nor is there a grub screw on that brass cap and it looks to be a R/H thread? But, it appears there was a circlip in there at one time, so I'll try a drop penetrating fluid overnight see if that helps

Radio Wrangler · 27th Mar 2017, 7:26 pm

There may well be a circlip to retain the centre shaft inside that brass cap, along with a steel ball to support the turntable weight.

Direct drive motors use pancake coils, so the riding height of the turntable sets the magnetic gap, which is important. I wonder if this cap operates as a height adjustment with a locking screw of some sort down that little hole? Along with some oil!

The ring above it al may be a retainer for all that we see, the stationary part of the bearing. The cylinder has a different colour to the cap, so it may well be something like oilite bronze with a plain brass for the endcap. The end of the cylinder has a conical reduction in radius which is likely to be a tool clearance for thread-cutting.

All finest guesswork.

If the hole is a locking screw, and there is a circlip inside releasing it may let the turntable off, taking a polished hardened steel shaft with it.

David

dseymo1 · 27th Mar 2017, 7:35 pm

Quote:

Originally Posted by paulsherwin

I agree it looks like belt drive, but it clearly has 'Direct Drive' printed on it.

So it does!

I was going by the 'finger holes', which are often there to assist in fitting the belt.

Info re oiling here

ITAM805 · 27th Mar 2017, 7:45 pm

Well, that was easy ! A squirt of switch cleaner and a quick blast with a hair dryer on full heat and off it came. It sits on a tapered shaft so the heat must have done the trick.

Quote:

Direct drive motors use pancake coils

David, you're right, and therein lies the next problem, the bearing is hidden under a shroud (like an upturned ashtray) which looks like it means a serious strip down

Thanks for link dseymo1

ITAM805 · 27th Mar 2017, 8:15 pm

Umm.. in that link the guy has a picture of a lube point covered with a plastic cap, I'm wondering whether my brass cap is simply a metal version ?

ITAM805 · 28th Mar 2017, 7:08 pm

Oh dear, in my efforts to remove the brass 'lubrication' cap, which wouldn't budge, the whole brass shaft turned, and it appears I've screwed up somehow as the motor shaft is now rubbing somewhere internally

27th Mar 2017, 4:37 pm	#1
ITAM805 Nonode Join Date: Jul 2010 Location: Folkestone, Kent, UK. Posts: 2,172	Hitachi turntable Split from this thread - I have this turntable from 1980 that I want to service. Not sure of the ID other than it's named 'Unitorque'. It runs intermittently so I'm guessing there's a power supply problem or perhaps a hidden micro switch? Can anyone help with how I get the platter off, and what to lube it with? There's a brass threaded cap underneath the spindle but it's on there pretty tight, molegrips wouldn't budge it ! Many thanks Attached Thumbnails

27th Mar 2017, 4:58 pm	#2
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,338	Re: Hitachi turntable This looks like it's a seperate unit from the rest of the kit, is that right? Is that the brass turntable boss you're trying to remove. Why? The platter will come off without putting a crude wrench on this. Use sewing machine oil to Lube. There should be a circlip on the centre spindle to release the platter. __________________ Edward.

27th Mar 2017, 5:14 pm	#3
dseymo1 Retired Dormant Member Join Date: Dec 2007 Location: Shropshire, UK. Posts: 3,051	Re: Hitachi turntable It looks like a typical Japanese belt-drive turntable. I'd expect the platter to lift off fairly easily, perhaps with a light tap from a mallet to the spindle while suspending the unit by the platter (takes two pairs of hands ideally). is the belt loose and slipping, perhaps? I'd use SAE 30 motor oil, but a few drops of pretty much any medium-bodied oil will do. Edit: Edward was replying at the same time. There may indeed be a circlip, but I can't see one in this case.

27th Mar 2017, 5:16 pm	#4
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,967	Re: Hitachi turntable I agree it looks like belt drive, but it clearly has 'Direct Drive' printed on it. There will be microswitches activated by the arm. All these DD autos are much of a muchness. I would also use something heavier than sewing machine oil, though it doesn't really matter so long as the main bearing is well lubricated.

27th Mar 2017, 5:42 pm	#5
ITAM805 Nonode Join Date: Jul 2010 Location: Folkestone, Kent, UK. Posts: 2,172	Re: Hitachi turntable Thanks guys. It's direct drive no belts. It doesn't just lift off and I can't see any circlips either? Edward, yes it's part of the music centre in the link. Thanks for the lube advice.

27th Mar 2017, 5:46 pm	#6
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Hitachi turntable Looks like it could be a brass shaft in a brass bearing. Does the turntable lift slightly so that the shaft slides in the bearing? There's a hole in the side of the shaft. Does it conceal a grub screw, or possibly accomodate a 'C' spanner? Left Hand Thread? __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

27th Mar 2017, 7:04 pm	#7
ITAM805 Nonode Join Date: Jul 2010 Location: Folkestone, Kent, UK. Posts: 2,172	Re: Hitachi turntable Thanks Graham, there's no up/down movement on the platter. Nor is there a grub screw on that brass cap and it looks to be a R/H thread? But, it appears there was a circlip in there at one time, so I'll try a drop penetrating fluid overnight see if that helps Attached Thumbnails

27th Mar 2017, 7:26 pm	#8
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,901	Re: Hitachi turntable There may well be a circlip to retain the centre shaft inside that brass cap, along with a steel ball to support the turntable weight. Direct drive motors use pancake coils, so the riding height of the turntable sets the magnetic gap, which is important. I wonder if this cap operates as a height adjustment with a locking screw of some sort down that little hole? Along with some oil! The ring above it al may be a retainer for all that we see, the stationary part of the bearing. The cylinder has a different colour to the cap, so it may well be something like oilite bronze with a plain brass for the endcap. The end of the cylinder has a conical reduction in radius which is likely to be a tool clearance for thread-cutting. All finest guesswork. If the hole is a locking screw, and there is a circlip inside releasing it may let the turntable off, taking a polished hardened steel shaft with it. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

27th Mar 2017, 8:15 pm	#11
ITAM805 Nonode Join Date: Jul 2010 Location: Folkestone, Kent, UK. Posts: 2,172	Re: Hitachi turntable Umm.. in that link the guy has a picture of a lube point covered with a plastic cap, I'm wondering whether my brass cap is simply a metal version ? Attached Thumbnails

28th Mar 2017, 7:08 pm	#12
ITAM805 Nonode Join Date: Jul 2010 Location: Folkestone, Kent, UK. Posts: 2,172	Re: Hitachi turntable Oh dear, in my efforts to remove the brass 'lubrication' cap, which wouldn't budge, the whole brass shaft turned, and it appears I've screwed up somehow as the motor shaft is now rubbing somewhere internally